Ultrasonic testing device

ABSTRACT

The specification discloses an ultrasonic testing device for non-destructively testing electrically welded steel tubing. The device comprises a mechanical mounting arrangement for one or more ultrasonic transducers which automatically tracks the path of movement of steel tubing through the device to insure substantially uniform positioning of the transducers with respect to the tubing notwithstanding deviations in the path of movement of the tubing. The device includes a box having a pair of aligned sealed openings through which the tubing passes, and in which the tubing and the ultrasonic transducers may be immersed in water which serves as a couplant for transmission of sound waves emitted from the transducers to the tubing and reflected back to the transducers.

"written maul Zeiters Inventor:

Assignee:

Filed:

Appl. No.:

ULTRASONIC TESTING DEVICE Donald L. Zeiters, Shelby, Ohio CopperheadSteel Company,

Pittsburgh, Pa.

Jan. 12, 1972 Gtlin 29/04 References Cited UNITED STATES PATENTSBoulanger et al 73/67.7

Primary Examiner-Richard C. Queisser Assistant Examiner-John P.Beauchamp Attorney-Buell, Blenko & Ziesenheim [57] ABSTRACT Thespecification discloses an ultrasonic testing device fornon-destructively testing electrically welded steel tubing. The devicecomprises a mechanical mounting arrangement for one or more ultrasonictransducers which automatically tracks the path of movement of steeltubing through the device to insure substantially uniform positioning ofthe transducers with respect to the tubing notwithstanding deviations inthe path of movement of the tubing. The device includes a box having apair of aligned sealed openings through which the tubing passes, and inwhich the tubing and the ultrasonic transducers may be immersed in waterwhich serves as a couplant for transmission of sound waves emitted fromthe transducers to the tubing and reflected back to the transducers.

10 Claims, 5 Drawing Figures Fig .5.

SHEET 20F 3 w l "UH .T

PATENTEU 91975 Fig .2. M

PATENIEDHBT ems SHEET 3 BF 3 ULTRASONIC TESTING DEVICE This inventionrelates to devices for nondestructively testing electrically weldedsteel tubing, as by ultrasonic transducers mechanically positionedrelative to the tubing as it moves from one station, such as asizingstation, to another station, such as the cut-off station.

Apparatus for non-destructively testing electrically welded steel tubingby the use of ultrasonic transducers has been heretofore known andemployed. However, such apparatus has proved unsatisfactory for thereason that the inspection transducer has to be calibrated in acalibration box and then shifted to the test box. The movement of theinspection transducer causes changes in the adjustment which nullify thecalibration. Moreover, the inspecting transducer is set up in a fixedposition and thus, due to deviations in the path of movement of thetubing and irregularities in the tubing itself, the probe of thetransducers does not focus continuously at the same level or point alongthe tubing with movement of the tubing.

In order to avoid the disadvantages and inaccuracies of the foregoingtesting apparatus, I propose to provide an improved testing apparatusinwhich a mechanical mounting arrangement for an ultrasonic transducerautomatically and exactly follows, that is tracks, the movements of theelectrically welded steel tubing so as to maintain uniformity ofphysical relationship between the tubing and the inspecting probe.

More specifically, I propose to provide mounting apparatus for anultrasonic testing device having tracking means in the form of aplurality of contoured rollers on which the tubing is supported andmoves, the rollers being in yielding contact with the tubing and movedin vertical and horizontal directions responsively to deviations in thepath of movement of the tubing, thereby to automatically andcorrespondingly adjust the position of the ultrasonic testing device soas to maintain the necessary uniformity of physical relationship betweenthe tubing and the testing device.

I furthermore provide mounting apparatus for an ultrasonic transducercomprising a test box having an open top and side walls with a pair ofaligned circular recesses in which a pair of double-lipped elastomericseals, such as neoprene, provide a sealed barrier against loss of waterfrom the box with the tubing moving through the recesses. The tubing isthus immersed in water and the inspection probe of the transducer issubmerged thereunder, the water providing a couplant through which soundwaves emitted from the probe are transmitted to and reflected back fromthe tubing.

1 additionally provide a testing device in which the test box and sealplates are made of high strength aluminum which provides a maximumresistance to corrosion and is of relatively light weight for easyhandling. Moreover, in the testing device which I provide, the test boxhas sufficient stability that the test instrument mounted thereon may becalibrated in place without removing the test box from the mill, thusavoiding the possibility of maladjustment of the inspection probe aftercalibration.

The above mentioned features are embodied in a presently preferredembodiment of my invention, shown in the accompanying drawings, wherein:

FIG. 1 is a front elevational view, a fragment being broken away forclarity;

FIG. 2 is a side elevational view;

FIG. 3 is a plan view of the test box with testing devices removed,showing the contour and relation of inner and outer enclosure wallsthereof;

FIG. 4 is an elevational view of the test box, showing additionaldetails of the inner and outer enclosure walls; and

FIG. 5 is a profile view, on enlarged scale, of a seal assembly.

Referring to the drawings, the embodiment of the testing device 10 showncomprises a generally rectangular base weldment having a guide column 11at each of the four corners supported in a vertical position by tiechannels 12 extending therebetween and welded thereto. A mounting plate13 is provided at opposite ends of the base weldment attached as bywelding to the guide columns 11 and tie channels 12. A pair of gussetplates 14 interposed in the angle between each mounting plate 13 and thetie channels 12 between guide columns serves to strengthen thestructure. The entire weldment rests on a base plate 15 and is securedthereto by screws 16 extending through holes 17 in the end mountingplates.

Each of the guide columns 11 has a central bore 18, in the upper end ofwhich is supported a flanged bearing bushing 19. Telescopicallysupported in slidable relation in each of the bearing bushings 19 is avertically extending guide pin 20. Secured as by screws 21 to the upperface of the enlarged end of guide pins 20, in parallel spaced relation,are a pair of carrier shaft support rails 22, (FIG. 2) each rail havinga carrier shaft 23 secured in longitudinal alignment with the top edgeof the rail as by screws (not shown).

Supported on the carrier shafts 23 through intervening pillow blocks 24of the open ball bushing type is a platform channel 25, to the top faceof which a test box 26 is removably attached as by a plurality of toggleclamps 27. The pillow blocks 24 are dependingly attached as by screws tothe lower surface of the channel 25, two blocks engaging each carriershaft 23 in longitudinally spaced relation.

The platform channel 25 and test box 26 are yieldingly supported inelevated position by an air cylinder 27 through the medidum of a slidebase 28. Slide base 28 is a steel weldment of generally rectangularshape comprising four corner guide blocks 29 and tie channels 30connecting and welded to the blocks. Each of the blocks 29 has a throughbore 31, in the upper end of which is fitted a flanged bearing bushing32. The slide base 28 is mounted for vertical slidable movement on theguide pins 20 which extend through the bearing bushing 32 incorresponding guide blocks 29. A plurality of helical springs 33, eachdisosed concentrically around a corresponding guide pin 20 inintervening relation between the shoulder of the enlarged end of theguide pin and the flange of .the bearing bushing 32, serve to yieldinglysupport the platform channel and test box. Shims in the form of washersmay be interposed between the springs 33 and the bearing bushings 32 toprovide adjustment to obtain appropriate working height for the platformand test box.

The air cylinder 27 has a flanged base 34 at one end, which is attachedas by screws 35 to the base plate 15. The piston rod 36 of the cylinderextends vertically upward from the opposite end and is screwed into atapped bore 37 in a cross plate 38 bridging and welded to opposite tiechannels 30 of the slide base. The connection of the piston rod 36 tothe cross-plate 38 is reinforced by a collar 39 welded to thecross-plate and having a tapped bore forming an extension of the tappedbore 37 of the cross-plate.

Attached as by welding to one of the guide blocks 29 of the slide base28 is a mounting plate 40 having parallel extending slots 41 by which toadjustably mount a microswitch 42. Microswitch 42 has an actuating arm43 which extends upwardly in registry with a notch or recess 44 cut intothe lower edge of one of the side flanges of the platform channels 25.Microswitch 42 is actuated for a desired purpose, such as to provide asignal, by engagement of the arm 43 with the side wall of recess 44 inthe flange of the platform channel. Such engagement might occur uponexcessive lateral movement of the platform channel 25 from its normalposition. The manner in which the platform channel 25 is shiftedlaterally will be described later. Collars 45 secured as by set screwsto the ends of the carrier shafts 23 and engageable by the pillow blocks24 serve to limit the lateral movement of the platform channel on thecarrier shafts 23.

The test box 26 comprises a bottom plate 45, to which an inner enclosurewall 47 and an outer enclosure wall 48 are welded, as particularly shownin FIG. 3. The plate 46 and enclosure walls 47 and 48 are preferably ofaluminum material to minimize the weight of the assembly.

The enclosure walls 47 and 48 severally formed out of single sheets ofappropriate thickness (e.g. 0.19 inch), and length, bent intoappropriate contour and welded together at the juncture ofthe oppositeends of the sheet. As will be noted in FIG. 3, the enclosure walls areplaced edgewise on the bottom plate 46 and welded thereto. In addition,the inside surface of each wall is sealingly bonded to the bottom plate,as by an epoxy cement, to prevent leakage of water from the interior ofthe enclosure.

As will be seen from FIGS. 1 and 4, the upper edge surface of the innerenclosure wall 47 is of irregular height above the bottom plate 46, thediagonally opposite corner sections being higher relative to the bottomplate than the remaining sections, each corner section serving as amounting bracket for an ultrasonic testing device 49, hereinafterreferred to and described more fully later on.

Two parallel low sections of the enclosure wall 47 contain similaraligned U-shaped openings 50. Attached to the wall as by screws inregistry with each opening 50 is a seal assembly 51. As shown in FIG. 5,each seal assembly 51 comprises a sandwich of two outer plates 52 ofsuitable sheet material, such as aluminum, two inner plates 53 of rubbermaterial such as neoprene, and a separator strip 54 of suitable materialsuch as brass, the assemblage being held together by a plurality ofscrews extending through the holes in the intervening plates andengaging tapped holes in the outer plate 52. The separator plate is ofslightly greater thickness (e.g. 0.20 inch) than is the enclousre wall47 and thus the seal assemblies 51 are secured to the wall at theU-shaped openings 50 in stradling relation.

Depending on the diameter of tubing to be tested, the outer and innerplates 52 and 53 of the pairs of seal assemblies 51 have circularopenings of appropriate diameter, through which tubing to be testedextends. The circular openings in the inner plates 53 of neoprene aresomewhat smaller in diameter than the circular openings in the outerplates 52 so as to allow some flexibility in the circular lip of theneoprene seal.

The outer enclosure wall 48, which is relatively low in height comparedto the enclosure wall 47, is of foursided rectangular contour andsurrounds the enclosure wall 47 in outwardly spaced relation so as toform a moat therebetween for the collection of water which may spillover the top edge of the inner enclosure wall 47. As will be seen inFIG. 1, water may be supplied to the inner enclosure through a hoseconnected to an elbow fitting 55 mounted in the enclosure wall adjacentthe bottom plate 46. Spillage into the moat formed by the outer wall 48may be drained through a hose (not shown) connected to a fitting 56mounted in the outer wall 48.

Mounted outside opposite sides of the outer enclosure wall 48, inalignment with each other and the two seal assemblies 51, are a pair ofcontoured tracking rollers 57, on which the tubing 58 being tested issupported. As seen in FIG. 1, the rollers 57 are rotatably mounted, asby suitable ballbearing races at each end, on a shaft 59. The oppositeends of shaft 59 extend through holes in spaced arms of a U-shapedbracket 60 attached as by screws to the bottom plate 46, each of therollers 57 thereby being supported for rotation on a horizontal axis.

The outer surface of each of the rollers 57 is of corresponding shallowsymmetrical concave contour, the low point of the concave surface beingmidway between the opposite ends of the roller.

The tubing 58 resting on rollers 57 tends to seek the low point of theconcave surface of the rollers on which to rest. Thus, if thelongitudinal axis of the tubing 58 lies in the vertical plane throughthe center line 61 (FIG. 1) of the tubing device 10, the low point ofthe concave surface of rollers 57 will correspondingly lie in the samevertical plane. However, if the longitudinal axis of the tubing 58deviates to right or left out of the vertical plane through the centerline 61, the rollers 57 will be shifted correspondingly until the tubingagain rests on the low point of the concave surface on the rollers. Itwill thus be seen that, being attached to and movable with the rollers57, the test box 26 and the platform channel 25 are also correspondinglyshifted laterally by reason of the substantially frictionless pillowblocks 24 supporting the platform channel 25 on the carrier shafts 23.

Obviously, if the tubing 58 deviates different degrees from the verticalplane through the center line 61 of test device 10 at the oppositerollers 57, the rollers 57 will assume an average position correspondingto the average of the different deviations at the different rollers.

The mounting arrangement for rollers 57 will thus be seen to track orfollow the longitudinal axis of the tubing so that the physical relationof the tubing and the test box 26 will remain substantially uniform.

The ultrasonic testing devices 49 mounted on the inner enclosure wall 47of the test box 26 are thus correspondingly positioned in substantiallyuniform relation to the tubing 58 notwithstanding lateral deviations orirregularities in the path of movement of the tubing 58 through the testbox 26.

In the event of irregularities or distortion in the tubing 58 such thatthe tubing rises from the rollers 57, or

springs 33 biasing the supporting guide pins 20 upwardly expand tomaintain the rollers 57 in contact with the tubing or arecompressedcorrespondingly with corresponding upward or downward movement of theplatform channel 25 and test box 26 attached thereto.

It will be apparent, therefore, that by reason of the continual yieldingengagement of the tracking rollers 57 with the tubing 58 being tested,the plateform channel 25 and test box 26 attached thereto arecorrespondingly shifted in accordance with deviations in the path ofmovement of tubing 58 so as to maintain a uniform physical relationtherebetween. The importance of maintaining the uniform physicalrelation between the tubing being tested in the test box will beunderstood from the fact that the ultrasonic testing devices 49 areprovided with tubular inspection probes 62 which are disposed insubstantially radial relation to the tubing and the inspection lenses(not shown) adjacent the ends of the probes must remain in substantiallyconstant spaced relation to the outer surface of the tubing. Anyvariation in the spaced relation of the lenses with respect to the outersurface of the tubing will necessarily affect the accuracy of thereaction to the sound waves as reflected from the tubing being tested.Unless the physical relation between the test box 26 and the tubing 58is maintained, erroneous indications may result as to the soundness orintegrity of the welded section of the tubing. By insuring theuniformity of the physical relation between the test box 26 and thetubing being tested, the embodiment of my invention herein describedinsures the accuracy of the testing of the tubing.

In operation, the testing device is located in the production line forthe tubing between the sizing operation and the equipment for performinga cutting-off operation, that is, to cut the tubing to desired lengths.As viewed in FIG. 2 of the drawings, the tubing moves from right toleft, or vice versa. The water is supplied to the inner enclosure withinwall 47 of the test box 26 to a level sufficient to immerse the tubingsubstantially entirely therein. The inspection probes 62 similarly aresubmerged below the level of the water contained within the wall 47. Thewater thus provides a couplant for transmission of sound waves emittedfrom the probes 62 to the tubing and reflected back to the probes 62.This arrangement enables continuity of movement of tubing through theproduction line uninterruptedly while maintaining a constant supervisionand inspection of the welded seam in the tubing.

The seal assemblies 51 serve not only to maintain a seal on the tubingto prevent leakage of water therealong from within the inner enclosurewall 47 but also, by providing an air space between the inner rubberlayers'53, serve to dampen shock waves, arising from the subsequentcutting-off operation, which may interfere with operation of theultrasonic inspection devices 49.

While a presently preferred embodiment of my invention has beenspecifically described herein, it will be apparent that modificationsand alterations may be made therein within the terms of the appendedclaims.

I claim:

1. Ultrasonic apparatus for testing the integrity of welded steel tubingmoving therethrough, said apparatus comprising a test box enclosurethrough which welded tubing to be tested is moved, ultrasonic trans-2r..taan @at!i .iaa fixed g tionx nsa q n l Whph .v sure means movablyunting said enclosure, and

track i r g rr reans comprising a plurality of aligned rollers attached535m test box enclosure andea ch roller having a concave surface onwhich tubing is supported for movement through said enclosure.

2. Ultrasonic apparatus for testing the integrity of welded steel tubingaccording to claim l, wherein said means movably mounting the enclosurecomprises a platform member on which said test box enclosure isremovably attached, means movably mounting said platform member for freelateral movement, and base means yieldingly supporting said platformmember via said movably mounting means and urging said rollers in biasedrelation to the tubing.

3. Ultrasonic apparatus for testing the integrity of welded steel tubingaccording to claim 2, wherein the said means movably mounting theplatform member comprises a plurality of carrier shafts in parallelrelation to each other, anti-friction bearing members attached to andmounting said platform member on said carrier shafts for lateralmovement relative to the path of movement of the tubing, said alignedrollers attached to said test box enclosure being effective upon lateraldeviation of the tubing from a predetermined path of movement to moveresponsively according to the lateral deviation of the tubing tocorrespondingly laterally move the platform member and the test boxenclosure secured thereon.

4. Ultrasonic apparatus for testing the integrity of welded steel tubingaccording to claim 1, wherein said test box enclosure comprises a basemember, an inner enclosure wall attached to said base member on whichsaid ultrasonic transducer means is supported and an outer enclosurewall, attached to said base member in surrounding relation to the saidinner enclosure wall.

5. Ultrasonic apparatus for testing the integrity of welded steel tubingaccording to claim 3, wherein said base means supporting said carriershafts, comprises spring means for resiliently supporting said carriershafts and urging said rollers upwardly against the tubing restingthereon, whereby said test box follows correspondingly any verticaldeviation of the tubing from a predetermined path of movement.

6. Ultrasonic apparatus for testing the integrity of welded steel oftubing according to claim 4, wherein said inner enclosure wall has aninlet via which liquid is introduced therein and wherein said outerenclosure wall has an outlet via which to drain liquid which overflowssaid inner enclosure wall.

7. Ultrasonic apparatus for testing the integrity of welded steel tubingaccording to claim 4, wherein said inner enclosure wall comprises twowall sections in spaced substantially parallel relation, said wallsections having respective openings in aligned relation to each other,and seal assemblies mounted on said wall sections within said openingsfor providing a seal on the tubing so as to contain liquid within thesaid inner enclosure wall to a levelto effect immersion of the saidtransducer means and of the tubing as it moves through the space withinsaid inner enclosure wall.

8. Ultrasonic apparatus for testing the integrity of welded steel tubingaccording to claim 4, wherein said outer enclosure wall is relativelylow in height above 7 said base member compared to the said innerenclosure wall, and wherein said plurality of concave rollers are somounted on the said base member as to support the tubing for movementthrough 'the space within the inner enclosure wall at a level above thesaid outer enclosure wall.

9. Ultrasonic apparatus for testing the integrity of welded steel tubingaccording to claim 5, wherein said base means comprises a main basehaving a rectangular shape with a vertical guide block at each of thefour corners thereof in which guide rods are telescopically supported, aslide base having corner guide blocks slidable on said guide rods, andair cylinder means having a piston and piston rod, the latter beingconnected to said slide base, pressurization of said air cylinder meanssupporting said slide base in an elevated position in which said biasingmeans is effective.

10. Ultrasonic apparatus for testing the integrity of welded steeltubing according to claim 7, wherein each of said seal assembliescomprises a sandwich of two outer plates of metal, two inner plates ofelastomeric material, a separator strip between the two inner plates,and screw means holding said plates and strips together, the said innerplates having uniform sized openings therein for sealingly engaging thetubing as it moves therethrough, and the said outer plates havinguniform sized openings therein slightly larger in crosssection than theopenings in the said inner plates.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,763,695 Dated October 9 1973 Inventor(s) DONALD L. ZEITERS I It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

The assignee, indicated as "COP PERHEAD STEEL COMPANY" should read-COPPERWELD STEEL COMPANY-.

Column 2, line 44, "medidum" should read -medium--.

Colunm 2, line 53, "disosed" should read -disposed-.

Column 3, line 23, "45" should read --46-.

Column 3', line 59, "enclousre" should read -enclosure--.

Column 3, line 61, "stradling" should read straddling.

Signed and sealed this 2nd day of April 1971 (SEAL) Attest:

EDWARD M.FLETCHER,JR. G. MARSHALL DANN Atte sting Officer Commissionerof Patents ORM PC4050 (169) USCOMM-DC 6037G-P69 it U.S. GOVERNMENTPRINTING OFFICE: I969 O366-334,

1. Ultrasonic apparatus for testing the integrity of welded steel tubingmoving therethrough, said apparatus comprising a test box enclosurethrough which welded tubing to be tested is moved, ultrasonic transducermeans carried in a fixed position on said enclosure, means movablymounting said enclosure, and means fixed to said mounting means fortracking said tubing and effecting movement of said test box enclosureaccording to deviations in the path of movement of said tubing tomaintain a uniform physical relation between the said transducer meansand the tubing, said tracking means comprising a plurality of alignedrollers attached to said test box enclosure and each roller having aconcave surface on which tubing is supported for movement through saidenclosure.
 2. Ultrasonic apparatus for testing the integrity of weldedsteel tubing according to claim 1, wherein said means movably mountingthe enclosure comprises a platform member on which said test boxenclosure is removably attached, means movably mounting said platformmember for free lateral movement, and base means yieldingly supportingsaid platform member via said movably mounting means and urging saidrollers in biased relation to the tubing.
 3. Ultrasonic apparatus fortesting the integrity of welded steel tubing according to claim 2,wherein the said means movably mounting the platform member comprises aplurality of carrier shafts in parallel relation to each other,anti-friction bearing members attached to and mounting said platformmember on said carrier shafts for lateral movement relative to the pathof movement of the tubing, said aligned rollers attached to said testbox enclosure being effective upon lateral deviation of the tubing froma predetermined path of movement to move responsively according to thelateral deviation of the tubing to correspondiNgly laterally move theplatform member and the test box enclosure secured thereon. 4.Ultrasonic apparatus for testing the integrity of welded steel tubingaccording to claim 1, wherein said test box enclosure comprises a basemember, an inner enclosure wall attached to said base member on whichsaid ultrasonic transducer means is supported and an outer enclosurewall, attached to said base member in surrounding relation to the saidinner enclosure wall.
 5. Ultrasonic apparatus for testing the integrityof welded steel tubing according to claim 3, wherein said base meanssupporting said carrier shafts, comprises spring means for resilientlysupporting said carrier shafts and urging said rollers upwardly againstthe tubing resting thereon, whereby said test box followscorrespondingly any vertical deviation of the tubing from apredetermined path of movement.
 6. Ultrasonic apparatus for testing theintegrity of welded steel of tubing according to claim 4, wherein saidinner enclosure wall has an inlet via which liquid is introduced thereinand wherein said outer enclosure wall has an outlet via which to drainliquid which overflows said inner enclosure wall.
 7. Ultrasonicapparatus for testing the integrity of welded steel tubing according toclaim 4, wherein said inner enclosure wall comprises two wall sectionsin spaced substantially parallel relation, said wall sections havingrespective openings in aligned relation to each other, and sealassemblies mounted on said wall sections within said openings forproviding a seal on the tubing so as to contain liquid within the saidinner enclosure wall to a level to effect immersion of the saidtransducer means and of the tubing as it moves through the space withinsaid inner enclosure wall.
 8. Ultrasonic apparatus for testing theintegrity of welded steel tubing according to claim 4, wherein saidouter enclosure wall is relatively low in height above said base membercompared to the said inner enclosure wall, and wherein said plurality ofconcave rollers are so mounted on the said base member as to support thetubing for movement through the space within the inner enclosure wall ata level above the said outer enclosure wall.
 9. Ultrasonic apparatus fortesting the integrity of welded steel tubing according to claim 5,wherein said base means comprises a main base having a rectangular shapewith a vertical guide block at each of the four corners thereof in whichguide rods are telescopically supported, a slide base having cornerguide blocks slidable on said guide rods, and air cylinder means havinga piston and piston rod, the latter being connected to said slide base,pressurization of said air cylinder means supporting said slide base inan elevated position in which said biasing means is effective. 10.Ultrasonic apparatus for testing the integrity of welded steel tubingaccording to claim 7, wherein each of said seal assemblies comprises asandwich of two outer plates of metal, two inner plates of elastomericmaterial, a separator strip between the two inner plates, and screwmeans holding said plates and strips together, the said inner plateshaving uniform sized openings therein for sealingly engaging the tubingas it moves therethrough, and the said outer plates having uniform sizedopenings therein slightly larger in cross-section than the openings inthe said inner plates.